1. Technical Field
The present invention relates to a liquid crystal display device and an electronic apparatus, and in particular, to a technique capable of realizing high contrast and wide viewing angle in a transflective liquid crystal display device having both reflective and transmissive modes.
2. Related Art
There has been suggested a liquid crystal display device in which images can be viewed by using external light in a bright place, as in a reflective liquid crystal display device, and by using an internal light source, such as a backlight or the like, in a dark place. Such a liquid crystal display device employing both reflective and transmissive modes switches between both the modes depending on the ambient brightness. This allows clear display even in a dark place as well as reduction of power consumption. For this reason, such a liquid crystal display device is particularly suitable for a display unit of a portable apparatus or the like. Hereinafter, this kind of liquid crystal display device is referred to as a ‘transflective liquid crystal display device’ in this specification.
As such a transflective liquid crystal display device, there has been suggested a liquid crystal display device in which a liquid crystal layer is interposed between an upper substrate and a lower substrate, and a reflection film, which is a metal film made of aluminum or the like and has openings for transmitting light formed thereon, is provided on an inner side of the lower substrate, the reflection film serving as a transflective plate. In this case, in the reflective mode, external light incident on the upper substrate side passes through the liquid crystal layer, is then reflected from the reflection film provided on the inner side of the lower substrate to pass through the liquid crystal layer again, and is then emitted from the upper substrate side to display images. On the other hand, in the transmissive mode, light emitted from a backlight, that is, light incident on the lower substrate side passes through the liquid crystal layer via the openings of the reflection film and is then emitted to the outside from the upper substrate side. Accordingly, of a region where the reflection film is formed, a region where the openings are formed becomes a transmissive display region and the remaining region becomes a reflective display region.
However, the transflective liquid crystal display device in the related art has a drawback due to a narrow viewing angle in the transmissive mode. This disadvantage results from the lack of freedom in optical design with the restriction that the reflective display has to be achieved by a single polarization plate provided at a viewer side because a transflective plate is provided on an inner side of a liquid crystal cell so that parallax does not occur. Accordingly, in order to eliminate such a drawback, there has been suggested a new transflective liquid crystal display device using vertical alignment. This new transflective liquid crystal display device has three characteristics, as follows:                (1) ‘VA (Vertical Alignment) mode’—in which liquid crystal having negative dielectric anisotropy is vertically aligned with respect to a substrate and this alignment is destroyed by applying a voltage.        (2) ‘multi-gap structure’—in which the thickness of the liquid crystal layer (a cell gap) in a transmissive display region is different from that of the liquid crystal layer in a reflective display region (for example, see Japanese Unexamined Patent Application Publication Nos. 11-242226 and 2002-350853).        (3). ‘alignment division structure’—in which projections are provided,in the center of the transmissive display region on a counter substrate such that the liquid crystal falls down in eight directions in a regular octagonal transmissive display region.        
For example, Japanese Unexamined Patent Application Publication No. 2002-350853 adopts the multi-gap structure. This is to optimize the retardation (phase difference) required for the transmissive display and the retardation required for the reflective display, since light contributing to displaying images passes through the liquid crystal layer once for the transmissive display while passing through the liquid crystal layer twice for the reflective display. In order to realize the multi-gap structure, it is common to make the thickness of the liquid crystal layer in a reflective display region equal to about half of the thickness of the liquid crystal layer in a transmissive display region by forming a resin layer in the reflective display region, for example, to form a step difference between the reflective display region and the transmissive display region.
However, when realizing such a structure within a liquid crystal cell, it is difficult to form the step difference and to prevent a slope (an inclined portion) of the resin layer from being generated at a boundary between the transmissive display region and the reflective display region. For this reason, the liquid crystal located at the slope of the resin layer is aligned obliquely with respect to a substrate surface although it is in a vertical alignment mode, which causes deterioration of display contrast.